Run-up speed and jumping ground reaction force of male elite gymnasts on vault in China.

Background: A high run-up speed and a big jumping ground reaction force are crucial to perform difficult movements and improving the quality of movement performance in the competition vault. However, the relationship between performance in the competition vault and run-up speeds, as well as jumping ground reaction force, still needs to be discovered in detail. Objective: We aimed to investigate the interrelations between different run-up speeds and jumping ground reaction force, and to explore the different requirements of performing different vault styles as well as difficult movements on run-up speed and jumping ground reaction force. Methods: The data, including vaulting run-up speed and jumping ground reaction force of 30 Chinese male elite gymnasts of performance testing, were analyzed. Descriptive statistics and Binary logistic regression analysis were used for statistical analysis. Results: There was no significant difference in the pedaling run-up speed between the Front handspring types and Cartwheel types (p > 0.05). The comparison between interval run-up speeds revealed that the last 5 m run-up speeds were faster during the 25 m run-up distance, and 30 m sprint speed was strongly associated with the 25 m vaulting run-up speed of Handspring and Cartwheel (r = 0.81, p < 0.01). There are significant differences in the jumping ground reaction force of different types and difficult movements (p < 0.01). When the D-score is greater than 4.6, the jumping ground reaction force will increase significantly. Jumping ground reaction force was strongly correlated with 25 m run-up speed (r = 0.715, p < 0.01), last 5 m run-up speed (r = 0.718, p < 0.01), and 30 m sprint speed (r = 0.704, p < 0.01) respectively, but not significantly associated with last 10-5 m run-up speed as well as before the last 10 m run-up speed (p > 0.05). Conclusions: The special requirement for run-up speed and jumping ground reaction force may vary as the difficult vault. Moreover, the optimization of interval run-up speeds and improvement of the 25 m run-up speed may contribute to the bigger jumping ground reaction force and increase the potential to perform more difficult Handspring/Cartwheel vaults. The topic may merit an interventional study to optimize run-up rhythm and improve lower limb strength for achieving higher run-up speeds and bigger jumping ground reaction force within the limited run-up distance to perform more difficult vaults for male elite gymnasts in China.

PA during the COVID-19 outbreak in China: a cross-sectional study.

COVID-19 has undergone several mutations and is still spreading in most countries now. PA has positive benefits in the prevention of COVID-19 infection and counteracting the negative physical and mental effects caused by COVID-19. However, relevant evidence has indicated a high prevalence of physical inactivity among the general population, which has worsened due to the outbreak of the pandemic, and there is a severe lack of exercise guidance and mitigation strategies to advance the knowledge and role of PA to improve physical and mental health in most countries during the epidemic. This study surveyed the effects of COVID-19 on PA in Chinese residents during the pandemic and provided important reference and evidence to inform policymakers and formulate policies and planning for health promotion and strengthening residents' PA during periods of public health emergencies. ANOVA, Kolmogorov-Smirnov, the chi-square test and Spearman correlation analysis were used for statistical analysis. A total of 14,715 participants were included. The results show that nearly 70% of Chinese residents had inadequate PA (95%CI 58.0%-82.19%) during the COVID-19 outbreak, which was more than double the global level (27.5%, 95%CI 25.0%-32.2%). The content, intensity, duration, and frequency of PA were all affected during the period of home isolation, and the types of PA may vary among different ages. The lack of physical facilities and cultural environment is the main factor affecting PA. However, there was no significant correlation between insufficient PA and the infection rate. During the period of home isolation and social distance of epidemic prevention, it is necessary to strengthen the scientific remote network monitoring and guidance for the process of PA in China.